Diaphragm pump protective system



Oct. 1, 1963 H. K. HOWERTON 3,105,442

DIAPHRAGM PUMP PROTECTIVE SYSTEM Filed Dec. 16, 1960 gr \\\\l Gnsdar 1 Juan/aw L4H vs HUGH K. HOWERTOA/ United States Patent hid.

Filed Dec. 16, 1960, Ser. No. 76,284 9 Claims. (Q1. 103-11) This invention relates to compressors and pumps of the diaphragm type, and more particularly to a warning and protective system for a pump or compressor of the type employing an oscillating diaphragm driven by an operating fluid as the means for compressing or pumping a gas.

A main object of the invention is to provide a novel and improved warning and protective system for use with a diaphragm pump of the type disclosed in US. Patent No. 2,662,478 to Francois Eugene Surre, the system being arranged to detect leakage of operating fluid associated with the pump and to provide a positive warning of such leakage as well as to cutoff the supply of gas to the pump, whereby to prevent the formation of dangerously combustible mixtures of gas and vaporize-d operating fluid.

A further object of the invention is to provide an improved protective system for a diaphragm pump which is automatically operated to out oh the supply of gas to the pump when substantial leakage of operating fluid occurs therein, whereby to prevent the formation of combustible mixtures of gas and vaporized operating fluid in the pump and to reduce the hazards from the presence of such combustible mixtures, the system involving relatively simple parts, being highly sensitive, and providing a quantitative visual indication of the presence and amount of such leakage as well as an automatic alarm when the amount of leakage rises to a dangerous value.

A still further object of the invention is to provide an improved automatic operating fluid leakage detecting and alarm system, as well as an automatic supply valve controlling system for a diaphragm pump, said system involving relatively inexpensive components, being reliable in operation, and greatly reducing the explosion hazards of such pumps, especially when employed for pumping gases containing oxygen or other combustion-promoting ingredi ents.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a diagram showing the schematic piping and electrical connections of an improved diaphragm pump protective system constructed in accordance with the present invention.

F GURE 2 is a diagram showing a plan view of the optical arrangement employed in the operating fluid leakage detection component of the protective system of FIGURE 1.

Referring to the drawings, 11 generally designates a cross-sectional portion of a diaphragm pump of the type disclosed in US. Patent No. 2,662,478 to Francois Eugene Surre, said pump comprising a pair of plates 12 and 13 defining between them a biconical compression chamber 14. The plate member 12 is provided with suitable gas intake and delivery valves (not shown) provided in ports communicating with the gas supply and delivery conduits shown respectively at 15 and 16, while dddSAdZ Patented Oct. 1, 1963 ice 2 the plate 13 is formed with perforations or ports 17 through which an operating fluid, such as oil or glycerine, is alternately discharged and sucked, by a piston, not shown, acting in the pump body 18. Mounted across the chamber 14 is a composite diaphragm assembly consisting of three thin diaphragm elements 19, 29 and 21, arranged one upon the other, clamped together at their periphery between the plates 12 and 13, and movable in vibratory reciprocation as a single unit under the action of the operating fluid within the compression chamber 14, thus causing correlated suction and discharge of the gas on the face of the diaphragm assembly opposite from that subjected to the action of the driving fluid. The two outer'diaphragm elements 2t) and 21 are solid or imperforate, whereas the central diaphragm element 19 is formed with radial grooves 22 on both sides thereof, extending from a point adjacent to its center to the periphery of said diaphragm element 19. The three dia-,

phragm elements 19, 2t and 21 extend with their periphery outwardly beyond the area in which they are clamped between the plates 12 and 13 into an annular recess 23 formed partly in each of the plates 12 and 13. The central diaphragm element 19 is extended further beyond this recess through a sealing ring 24 which seals the recess from the exterior. A duct 25 for-med in the lower plate 13 connects the lower side of the annular recess 23 with a conduit 25 leading to a detector assembly 27. A duct 23 formed in the upper plate 12 connects the upper side of the annular recess 23 with a conduit 29 leading to another detector device, not shown.

Should the upper diaphragm element 20 become punctured or cracked for any reason, part of the gas subjected to compression will flow out through the puncture or crack in the diaphragm element 20 and through the radial grooves 22 of central element 19, thence through the upper half of chamber 23 and out through the duct 2-8 and conduit 29 to operate the related gas leak detector.

If the lower diaphragm element 21 is the one punctured or cracked, then part of the operating fluid will ilow through such puncture or crack and the radial grooves 22 of central element 19 and through the lower half of chamber 23 and out through the duct 25 and conduit 26 to the safety control detector device 27 to shut off the supply of gas to the pump at conduit 15 if the leakage exceeds a safe amount, as will be presently explained. It is very important to detect the leakage at this point, since if the leaking fluid reaches the upper portion of chamber 14, by further deterioration of the diaphragm, the fluid will vaporize and mix with the gas being pumped, in many cases =forming a highly combustible mixture therewith and creating -a substantial explosion hazard.

Slight defects may produce a very slight leakage of the gas being pumped, or of the operating fluid, without any perforation of the diaphragm assembly. To vent the relatively slight amounts of fluid leaking without such perforation of the diaphragm and to prevent unnecessary or erroneous operation of the protective and leak detection equipment, a circumferential groove 31, vented to atmosphere, is provided in the clamping area of the lower plate 13, and a similar circumferential groove 30, also vented to atmosphere, is provided in the clamping aroaaaa 3 area of the upper plate 12. Thus, any leakage due to defects in the sealing areas will be vented to atmosphere.

If, however, the gas leakage results from the fact that the upper diaphragm element 20 is actually punctured, the gas will leak out through the upper grooves 22 in the central element 19 and out through the recess 23 and duct 28 to conduit 29 and the associated leak detector.

If leakage of the operating fluid occurs due to the tact that the lower diaphragm element 21 is punctured, the leaking fluid passes through the lower grooves 22 to the lower portion of recess 23, and thence to the device 27, as above described.

. The detector device 27 comprises a housing 32 having the inlet conduit 33 and the outlet conduit 34 aligned with inlet conduit 33, as shown. For example, housing 32 may be generally rectangular and the inlet conduit 33 may be connected to the central portion of the top wall thereof, with the outletconduit 34 connected to the central portion of the bottom wall of the housing. A suitable source of exciting radiation, such as an ultra-violet light source as, is mounted to emit radiation into the housing through an admission tube 37 connected to the central portion of a vertical wall 38 of the housing perpendicular to the path of vapor or gas flowing vertically through the housing. A light trap 39 is provided in the opposite vertical Wall of the housing to receive and suppress direct radiation reaching same.

A detector tube 49 is connected to a ventical wall 41 of the housing perpendicular to the direct path of radiation, and a photosensitive device 43, such as a photo cell or a photomultiplier tube 43 is mounted to receive radiation excited in the gas or vapor in the housing as a result of the impinging direct radiation from source 36.

A suitable fluorescent tracer material may be provided in the operating fluid, such as Fluorescein or 4 methylumbelliferone. Such fluorescent indicating material may be dispersed in a medium which is soluble in the operating fluid, so that in the event of leakage of said operating fluid into the detecting housing 32, the indicating material will fluoresce when excited by the radiation from source 37, and such fluorescence will activate the photosensitive device 43 and generate an electrical signal. The output of device 43 is amplified in a suitable amplifier 44 and is applied to an indicating meter 45 of the relay type.

The meter 45 is provided with a conductive indicating arm 46 which is engageable with a stationary contact 47 at a signal value corresponding to an upper safe leakage limit;

As shown diagrammatically in FIGURE 2, the housing 32 is provided'with suitable low fluorescence windows transparent to ultraviolet light, shown at 48 and 49, such as'silica windows, for transmitting the radiation from the source 36 to the interior of the housing and from the fluorescing indicating material to the photo-sensitive device 43.

A visual or audible alarm device 54 is provided, said device being connected in circuit with a battery 51, or other suitable current source, and with the contact elements 46 and 47. Thus, the conductive indicating arm 46 is connected by a wire 52 to one terminal of the current source 51. A wire 53 is connected to the stationary contact 47. One terminal of the alarm device 50 is connected to wire 53 and the other terminal thereof is connected to a wire 54, which is connected in turn to the remaining terminal of source 51.

Wires 53 and 54 are connected to the winding of a relay 55 having an armature 56 which normally engages a contact 57. A solenoid valve 58 is provided in the gas supply conduit 15. The winding of valve 58 is connected to a pair of current supply wires 59 and 6% through armature 56' and contact 57. Valve 53 is open when energized and closed when deenergized. Therefore, when arm 46 engages contact 47, relay 55 becomes energized through a circuit comprising source 51, wire 52, arm 45, contact 47, wire 53, the winding of relay 55, and wire 54, disengaging armature 56 from contact 57. This deenergizes the solenoid valve 58, causing it to close and to cut off the supply of gas to the conduit 15. The alarm device 5% simultaneously becomes energized, providing the warning signal indicating that there is excessive leakage of the operating fluid.

The meter 45 provides a continuous indication showing the amount of leakage so that it is possible to ascertain at all times whether or not the pump is in a safe condition and to detect the failure or deterioration of the lower diaphragm element 21 even before the leakage reaches an unsafe amount.

While a specific embodiment of an improved protective system for a diaphragm pump or compressor has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a fluid operating apparatus, two plates defining a chamber therebetween, :a composite diaphragm assembly extending across said chamber and clamped at its periphery to divide said chamber into two half-chambers, respective intake and discharge conduit means connected to one of said half-chambers for the intake and discharge of a first fluid into and from said one of said half-chambers, an operating'fluid containing fluorescent material, means to admit said operating fluid into and to discharge said operating fluid from the other half-chamber, said diaphragm assembly comprising at least a first and a second lamination respectively adjacent said one and said other halfchamber, the plate containing said other halfchamber being formed with a peripheral recess outwardly of its clamping area, sealing means arranged between the plates outwardly of said recess, said first lamination being formed with outwardly extending grooves facing the second lamination and extending across the clamping area, conduit means connected to said recess and including a housing, a source of exciting radiation mounted to emit exciting radiation in one direction into said housing, a photo-sensitive device mounted to receive fluorescent ra diation from operating fluid in said housing in a direction normal to said one direction, and electrically responsive means connected to said photo-sensitive device so that said electrically responsive means is actuated upon leakage of said operating fluid through said second lamination.

2. In a fluid operating apparatus, two plates defining a chamber therebetween, a composite diaphragm assembly extending across said chamber and clamped at its periphery to divide said chamber into two half-chambers, respective intake and discharge conduit means connected to one of said half-chambers for the intake and discharge of a first fluid into and from said one of said half-chambers, an operating fluid containing fluorescent material, means to admit said operating fluid into and to discharge said operating fluid from the other half-chamber, said diaphragm assembly comprising at least a first and a second lamination respectively adjacent said one and said other half-chamber, the plate containing said other halfchamber being formed with a peripheral recess outwardly of its clamping area, sealing means arranged between the plates outwardly of said recess, said first lamination being formed with outwardly extending grooves facing the second lamination and extending across the clamping area, conduit means connected to said recess and including a housing, a source of exciting radiation mounted to emit exciting radiation in one direction into said housing, a photo-sensitive device mounted to receive fluorescent radiation from operating fluid in said housing in a direction normal to said one direction, and an electrically operated signal-responsive indicating device connected to said photo-sensitive device so that said indicating device is actuated upon leakage of said operating fluid through said second lamination.

3. In a fluid operating apparatus, two plates defining a chamber therebetween, a composite diaphragm assembly extending across said chamber and clamped at its periphery to divide said chamber into two half-chambers, respective intake and discharge conduit means connected to one of said half-chambers for the intake and discharge of a first fluid into and from said one of said half-chambers, an operating fluid containing fluorescent material, means to admit said operating fluid into and to discharge said operating fluid from the other half-chamber, said diaphragm assembly comprising at least a first and a second lamination respectively adjacent said one and said other half-chamber, the plate containing said other halfchamber being formed with a peripheral recess outwardly of its clamping area, sealing means arranged between the plates outwardly of said recess, said first lamination being formed with outwardly extending grooves facing the second lamination and extending across the clamping area, conduit means connected to said recess and including a housing, a source of exciting radiation mounted to emit exciting radiation in one direction into said housing, a photo-sensitive device mounted to receive fluorescent radiation from operating fluid in said housing in a direction normal to said one direction, an electrically operated signal-responsive indicating device provided with a pair of contacts closing responsive to a signal of predetermined magnitude connected to sm'd photo-sensitive device, an electrical alarm device, and an energizing circuit connected to said alarm device through said pair of contacts so that said alarm device is actuated upon leakage of said operating fluid through said second lamination.

4. in a fluid operating apparatus, two plates defining a chamber therebetween, a composite diaphragm assembly extending across said chamber and clamped at its periphery to divide said chamber into two half-chambers, respective intake and discharge conduit means connected to one of said half-chambers for the intake and discharge of a first fluid into and from said one of said half-chambers, a normally open valve in said intake conduit means, an operating fluid containing fluorescent material, means to admit said operating fluid into and to discharge said operating fluid from the other half-chamber, said diaphragm assembly comprising at least a first and a second lamination respectively adjacent said one and said other half-chamber, the plate containing said other half-chamher being formed with a peripheral recess outwardly of its clamping area, sealing means arranged between the plates outwardly of said recess, sm'd first lamination being formed with outwardly extending grooves facing the second lamination and extending across the clamping area, conduit means connected to said recess and including a housing, a source of exciting radiation mounted to emit exciting radiation in one direction into said housing, means to receive fluorescent radiation from operating fluid in said housing in a direction normal to said one direction, and means to close said valve responsive to a predetermined level of intensity of said last-named radiation so that said valve is closed upon leakage of said operating fluid through said second lamination.

5. In combination, a fluid operated device comprising a chamber, a laminated flexible diaphragm sealingly secured in said chamber and defining a driving fluid space on one side thereof and a fluid pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, said diaphragm comprising at least two laminations respectively adjacent the driving fluid space and the pumping space, means defining a leakage channel between the laminations and extending to the periphery of the chamber, means defining a leakage fluid cavity, means communicatively connecting said cavity with said channel, conduit means connected to said cavity, a source of exciting radiation, means to direct radiation from said source into said conduit means in one direction a photo-sensitive device mounted to receive fluorescent radiation from driving fluid in the conduit means in a direction normal to said one direction, and indicating means operatively connected to said photosensitive device so that said indicating means is operated upon leakage of said driving fluid through the lamination adjacent the driving fluid space.

6. In combination, a fluid operated device comprising a chamber, a laminated flexible diaphragm sealingly secured in said chamber and defining a driving fluid space on one side thereof and a fluid pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, respective fluid inlet and outlet conduit means connected to said pumping space, a norrnally open valve in said inlet conduit means, said diaphragm comprising at least two laminations respectively adjacent the driving space and the pumping space, means defining a leakage channel between the laminations and extending to the periphery of the chamber, means defining a leakage fluid receiving cavity, means communicatively connecting said cavity with said channel, conduit means connected to said cavity, a source of exciting radiation, means to direct radiation from said source into said lastnamed conduit means in one direction, a photo-sensitive device mounted to receive fluorescent radiation from driving fluid in said last-named conduit means in a direction normal to said one direction, and means to close said valve responsive to a predetermined level of response of said photo-sensitive device so that said valve is closed upon leakage of said driving fluid through the lamination adjacent the driving space.

7. In combination, a fluid operated device comprising a chamber, a flexible diaphragm mounted in said chamber and defining a driving space on one side thereof and a pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, said diaphragm comprising at least two laminations, means defining a leakage channel between the laminations and extending to the periphery of the diaphragm, conduit means communicatively connected to said leakage chwnel, a source of exciting radiation mounted to emit radiation into said conduit means in one direction, means to receive fluorescent radiation from driving fluid in said conduit means in a direction normal to said one direction, and indicating means located to respond to said last-named radiation so that said indicatingrneaus is operated upon leakage of said driving fluid through the lamination adjacent said driving space.

8. In combination, a fluid operated device comprising a chamber, a flexible diaphragm mounted in said chamber and defining a driving space on one side thereof and a pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, respective fluid supply and discharge conduit means connected to said pumping space, said diaphragm comprising at least two laminations, means defining a leakage channel between the laminations and extending to the periphery of the diaphragm, conduit means communicatively connected to said leakage channel, a source of exciting radiation mounted to emit radiation into said conduit means in one direction, means to receive fluorescent radiation from driving fluid in said conduit means in a direction normal to said one direction, valve means in said fluid supply conduit means, and means to close said valve means responsive to a predetermined intensity level of said last-named radiation so that said valve means is closed upon leakage of said driving fluid through the lamination adjacen said driving space.

9. In combination, a fluid operated device of the type comprising a chamber, a flexible diaphragm mounted in said chamber and defining a driving space on one side thereof and a pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, and fluid inlet and dischmge conduit meansconnected to said pumping space, leak detection conduit means, leakage channel-defining means to communicatively connect said leak detection conduit means to said driving space responsive to leakage at least through the portion of said diaphragm adjacent said driving space, a source of exciting radiation mounted to emit radiation into said leak detection conduit means in one direction, and means to receive fluorescent radiation from driving fluid insaid leak detection conduit means in a direction normal to said one direction and including indicating means responsive to said last-named radiation so that said indicating means is actuated upon leakage of said driving fluid through said diaphragm portion.

References Cited in the file of this patent UNITED STATES PATENTS V Bendz Feb. 14, 1939 Fausek Aug. 10, 1948 Surre Dec. 15, 1953 Zeitlin et al Dec. 13, 1955 Olson Nov. 6, 1956 McGee Nov. 12, 1957 Mathisen Oct. 6, 1959 Kittrell Dec. 8, 1959 Williams Nov. 22, 1960 

1. IN A FLUID OPERATING APPARATUS, TWO PLATES DEFINING A CHAMBER THEREBETWEEN, A COMPOSITE DIAPHRAGM ASSEMBLY EXTENDING ACROSS SAID CHAMBER AND CLAMPED AT ITS PERIPHERTY TO DIVIDE SAID CHAMBER INTO TWO HALF-CHAMBERS, RESPECTIVE INTAKE AND DISCHARGE CONDUIT MEANS CONNECTED TO ONE OF SAID HALF-CHAMBERS FOR THE INTAKE AND DISCHARGE OF A FIRST FLUID INTO AND FROM SAID ONE OF SAID HALF-CHAMBERS, AN OPERATING FLUID CONTAINING FLUROESCENT MATERIAL, MEANS TO ADMIT SAID OPERATING FLUID INTO AND TO DISCHARGE SAID OPERATING FLUID FROM THE OTHER HALF-CHAMBER, SAID DIAPHRAGM ASSEMBLY COMPRISING AT LEAST A FIRST AND A SECOND LAMINATION RESPECTIVELY ADJACENT SAID ONE AND SAID OTHER HALF-CHAMBER, THE PLATE CONTAINING SAID OTHER HALFCHAMBER BEING FORMED WITH A PERIPHERAL RECESS OUTWARDLY OF ITS CLAMPING AREA, SEALING MEANS ARRANGED BETWEEN THE PLATES OUTWARDLY OF SAID RECESS, SAID FIRST LAMINATION BEING FORMED WITH OUTWARDLY EXTENDING GROOVES FACING THE SECOND LAMINATION AND EXTENDING ACROSS THE CLAMPING AREA, CONDUIT MEANS CONNECTED TO SAID RECESS AND INCLUDING A 